Core protractor



Aug. 22, 1939. v (5l KOTHNY '2,170,146

coRE PROTRACTOR Filed May 28, 1957 ff /F/VEYS.

Patented Aug. 22, 1939 PATENT OFFICE CORE PROTRACTOR Gottdank L. Kothny, Straord, Pa., assignor to Sperry-Sun Well Surveying Company, Phila= delphia, Pa., a corporation of Delaware Application May. 28, 1937, Serial No. 145,232

5 Claims.

u When a core istaken from a bore hole, either in the direction of. the axis of thebore hole or in some known direction forming an angle with the axis of the bore hole, it is frequently found that such core will penetrate the boundary between two strata with the .result that the boundary plane will be indicated as an ellipse on the cylindrical surface of the core, which ellipse may degenerate into a circle if the core has been taken perpendicular to the separating plane. Particularly when this plane appearingin the core approaches a position at right angles tothe axis of the core it is rather diiicult to determine the dip of this plane relative to the axis of the core, and its strike relative toany'marking which would be indicative of the azimuthal position of the core in the earth.

Accuratey determination of ther apparent dip and. strike of a boundary plane between strata is particularly necessary when the true dip-and strike of the strata which are penetrated are to be determined vfrom the data just mentioned together with the magnetic polarity of a core and the inclination and azimuthal .direction of the inclination of a bore hole at the point where the core is taken. This process is described, for example, in Herrick Patent 1,792,639, dated February 17, 1933,

It is the object of the present invention to provide a core protractor which will facilitate the accurate determinatio-n of the dip and strike of strata appearing in a core. In carrying out the invention, provision is made for the location of a sighting edge closely adjacent cores of different sizes, with means for rotating the core to determine with a high degree of accuracy both the `constants just mentioned.

The above and other ob-jects of the invention, particularly relating to details `of construction, will be apparent from the following description read in conjunction with the accompanying drawing, in Which: e

Figure 1 is an elevation, with a core partially broken away, showing a preferred embodiment of the invention; and

Figure 2 is an end elevation, partly in section, of the same.

The improved protractor comprises a base 2 on which there is secured a fixed standard 4 carrying the spindle 6 of a plate 8, which is provided with a centering pin I0 arranged to engage a,

corresponding opening in one end of a core C. Opposite the xed standard 4 and lined up with it is a movable standard I2 provided with a guiding member I4 projecting into a T-slot I6. Extending upwardly through an opening I8 in the base portion of the standard I2 is the shank of a bolt 25, the square head of which, indicated at 22, is located in the wide portion of the T-slot. Threaded on the upper end of this bolt and adapted to clamp the movable standard on the base is a wing nut 24. The shank of the bolt 2i) together with the guide I4 serves to align theV movable standard for movement to and from the xed standard 4 in the direction of the spindley 26 carried at its upper end and supporting a plate 3E) corresponding to plate 8 and, like it, provided with a centeringY pin 32 arranged to enter a central opening in the other end of a core C. The spindle 2E is provided with a knurled head 28 and the plate 3E) is provided with a pin 34 eccentric to the axis of the pins 32 and I0 and arranged to engage an eccentric opening in the core C so that the core may be rotated about its axis by manipulation of the knurledrhead 28. The spindle 26 and the core may be locked in xed position by means ofa clamping screw 36. By reason of the adjustability of the standard I2, cores of various lengths may be mounted in the apparatus.

Arranged for'Y movement at right angles to the axis of the core is a base 38 through an opening 42 of which there extends a bolt 4i) having a square head 44 located in a T-slot 45. A wing nut 46 is arranged to clamp the base 38 to the base plate 2. The base 33 carries a standard 43 on which is pivoted at 5B a blade 52. The lower end of this blade 52 is arranged to move adjacent a scale 54, which is graduated to indicate the angle of slope of the edge of the blade 52 relative to a plane perpendicular to the axis of a mounted core. The face of the blade 52 adjacent the core and the face of the protractor scale 54 preferably lie in a plane which, by adjustment of the base 38, may be brought into substantial tangency with the cylindrical surface of the core C. An opening 56 may be provided in the protractor adjacent the ninety degree mark thereof, in which a pencil may be inserted for the purpose of marking the position of the strike line.

The use of the apparatus Will be obvious from the above. The core C is mounted by proper adjustment of the standard I2 and Will, in general, show surface striations such as S indicating the traces with its cylindrical surface of the boundary planes of strata from which the core was taken.

Cra

Aii

The base 38 is then adjusted to bring the knife and protractor into substantial tangency With the surface of the core and, with the eye held at some distance from the apparatus, the core is then revolved until the striations appear to be straight lines, whereupon the blade 52 is rotated by Inainipulation of its pivot 50 into apparent parallelism with these straight lines. If after a first adjustment of the blade it does not appear that the striations are straight lines by comparison with the straight edge of the blade, then another rotation of the core and another adjustment of the blade may be made. A mark made through the opening 55 Will then indicate the position of a strike line extending through the axis of the core, While the dip of the strato relative to the ams of the core may be read directly from the relationship of the blade 52 to the protractor 54. The data thus obtained is, of course, relative to the axis of the core. If, for example, it is desired to determine the actual dip and strike of the strata appearing in the core, it is necessary to take into account also the magnetic properties of the core or the alignment of the core with respect to the core taking instruments, the position of which may be known, and the inclination and azimuth of the hole from Which the core was taken,

1t Will be clear that Variations may be made in the specific embodiment of the invention Without departing from its scope.

What I claim and desire to protect by Letters Patent is:

l. A core protractor comprising a support, means for engaging the ends of a cylindrical core to mount it on said support for rotation about its axis, a sighting member mounted on said support to pivot substantially in a plane tangent to the cylindrical surface of the core, said sighting member being provided with a straight edge located laterally of the pivotal mounting and having a length greater than the diameter of the core, and means for indicating the angle of slope of the sighting member relative to a plane perpendicula-r to the axis of the core.V

2. A core protractor comprising a support, axially adjustable means for engaging the ends of a cylindical core to mount it on said support for rotation about its axis, means for locking the core in an adjusted rotary position, a sighting member mounted on said support to pivot substantially in a plane tangent to the cylindrical surface of the core, said sighting member being pivoted on an axis located laterally of the axis of the core and being provided with a straight edge alignable with the straight line element of the core to which said plane is tangent, and means for indicating the angle of slope of the sighting member relative to a plane perpendicular to the axis of the core.

3. A core protractor comprising a support, ax ially adjustable means for engaging the ends of a cylindrical core to mount it on said support for rotation about its axis, a sighting member mounted on said support to pivot substantially in a plane tangent to the cylindrical surface of the core, said sighting member being provided with a straight edge located laterally of the pivotal mounting and having a length greater than the diameter of the core, and means for indicating the angle of slope of the sighting member relative to a plane perpendicular to the axis of the core.

4. A core protractor comprising a support, 4means for engaging the ends of a cylindrical core to mount it on said support for rotation about its axis, means for locking the core in an adjusted rotary position, a sighting member mounted on said support to pivot substantially in a plane tangent to the cylindrical surface of the core, said sighting member being pivoted on an axis located laterally of the axis of the core and being provided with a straight edge alignable with the straight line element of the core to which said plane is tangent, and means for indicating the angle of slope of the sighting member relative to a plane perpendicular to the axis of the core.

5. A core protractor comprising a support, means for engaging the ends of a cylindrical core to mount it on said support for rotation about its axis, a sighting member mounted on said support to pivot substantially in a plane tangent to the cylindrical surface of the core, means. for indicating the angle of slope of the sighting member relative to a plane perpendicular to the axis of the core and means for indicating the strike line of a stratum appearing in the core when said sighting member is parallel to the direction of strata in the core.

GOTTDANK L. KOTHNY. 

